The present invention relates generally to a connector and, more particularly, to a self-locking connector of the type in which a detent locking arrangement is provided between the coupling nut and the shell of one of the mating connector members of the connector.
While the present invention will be described specifically herein with connection with an electrical connector, it will be appreciated that the invention could also be applied to fiber optic connectors as well as other coupling arrangements such as those utilized for interconnecting fluid conduits or the like.
Electrical connectors used in high vibration environments, such as in an aircraft, may decouple, or demate, during use. This is particularly a problem in cylindrical type connectors which utilize threaded coupling nuts to maintain the connection between the plug and receptacle members of the connector. It is known in the art to provide a detent type self-locking coupling mechanism for the connector, which is operatively connected between the coupling nut on the plug connector member and the shell of either the plug or receptacle connector member. The detent locking mechanism may include balls mounted on a flange of the plug shell or projections or dimples stamped in a detent ring which is affixed to the shell. The locking mechanism may also include a locking ring which is rotatable with the coupling nut of the connector. The ring typically is formed with a circular array of holes or recesses which face in the direction of the balls. Typically the number of recesses exceeds the number of balls in the locking mechanism. Spring means is normally provided urging the balls into engagement with the locking ring so that the balls will snap into the recesses as the coupling nut is rotated. In some cases the detent projections are provided on resilient spring arms formed on an annular ring which is carried by the plug shell. The parts may be reversed so that the detent balls or projections are carried by the coupling nut and the locking ring is affixed to the shell. In a further arrangement, the detent recesses may be provided on the receptacle shell. The following United States patents disclose self-locking connectors of the type described above: U.S. Pat. Nos. 2,152,977; 3,462,727; 3,552,777; 3,669,472; 3,786,396; 3,808,580; 3,920,269; and 4,291,933.
In the prior art locking mechanisms of the type referred to above the balls or projections engage the detent recesses in the locking ring in unison. Typically, the number of balls and recesses are equal, or the number of recesses is greater than the number of balls and divisible by the number of balls. For example, it is typical to provide three locking balls in the locking mechanism and twelve detent recesses in the locking ring. Such an arrangement provides a locking or detenting action at intervals of 30.degree. of rotation of the coupling nut. When a coupling mechanism of this type is utilized with a connector having a single-start coupling thread embodying, for example, twenty-eight to sixteen threads per inch, the 30.degree. incremental locking steps provide the desired locking action. However, a finer angular articulation is required to properly lock rapid coupling thread systems such as a multistart Acme thread utilized on some electrical connectors. In one such coupling arrangement, a triple-start thread having a lead of 0.300 inches is required. In this case, use of 30.degree. locking intervals would result in an axial coupling motion of 0.025 inches per locking point, which would be too coarse to properly lock the coupling mechanism.
Thus, what is required and constitutes the object of the present invention is to provide a self-locking coupling mechanism for a connector in which the locking or detent action occurs at shorter angular intervals of rotation of the coupling nut.